Systems and methods for thermal management of vehicle sensor devices

ABSTRACT

Methods and systems for thermal management of sensors of a vehicle. The system includes a sensor that is attached to a vehicle, a temperature monitor configured to collect temperature data corresponding to the sensor, a processor, and a sensor cleaning subsystem. The sensor cleaning subsystem includes a cleaning fluid reservoir and a port that is positioned to direct cleaning fluid from the reservoir to the sensor. The processor is configured to: receive temperature data corresponding to the sensor from the temperature monitor, determine whether a current temperature of the sensor is less than a threshold temperature, and in response to determining that the current temperature is less than the first threshold temperature, cause the sensor cleaning subsystem to: heat the cleaning fluid, and initiate a cleaning cycle and direct the heated cleaning fluid to the sensor to heat the sensor.

BACKGROUND

This disclosure relates generally to controlling the temperature ofvehicle components and specifically to controlling the temperature ofvehicle sensor components.

Modern vehicles rely on sophisticated sensors to provide an associatedcomputer or controller with location and situational awarenessinformation such as the relative position of other vehicles, and thelocation of the vehicle relative to the traffic lanes. Such sensordevices are temperature sensitive with a preferred operationaltemperature range. If exposed to temperatures outside of the operationaltemperature range (e.g., when the internal temperature of the vehicle ishigh due to greenhouse effects), the sensor device may not operate orperform reliably. In some cases, the sensor device may even be subjectto a shortened lifespan.

Furthermore, some sensor devices (such as a parking assist camera) areinstalled on the outside of the vehicle. Hence, the interior coolingsystems of the vehicle cannot control the temperature of such externallyinstalled sensor devices. Finally, some vehicles are operated in hotclimates where the ambient air temperature is more than the upperthreshold of the temperature specification of various sensor devices,and which may also exacerbate the greenhouse effect inside the vehicle.

SUMMARY

Systems and methods for thermal managements of vehicle sensor devicesare disclosed. In an embodiment, a vehicle sensor system may include asensor that is attached to a vehicle, a temperature monitor configuredto collect temperature data corresponding to the sensor, a processor incommunication with the temperature monitor, and a sensor cleaningsubsystem. The sensor cleaning subsystem may include a cleaning fluidreservoir and a port that is positioned to direct cleaning fluid fromthe reservoir to the sensor. The processor may be configured to executethe method disclosed in this disclosure. The method may includereceiving temperature data corresponding to the sensor from thetemperature monitor and determine whether a current temperature of thesensor is less than a threshold temperature. If the current temperatureis determined to be less than the first threshold temperature, themethod may also include causing the sensor cleaning subsystem to heatthe cleaning fluid, and initiate a cleaning cycle to direct the heatedcleaning fluid to the sensor to heat the sensor.

Optionally, the threshold temperature may be greater than a lower boundof an operational temperature range of the sensor.

In one or more embodiments, the method may include before causing thesensor cleaning subsystem to initiate the cleaning cycle determiningwhether the vehicle is in a safe to clean mode. The cleaning cycle mayonly be initiated in response to determining that the vehicle is in asafe to clean mode.

Additionally and/or alternatively, the method may include, beforecausing the sensor cleaning subsystem to initiate the cleaning cycle,determining whether the vehicle is in an idle mode. The cleaning cyclemay only be initiated in response to determining that the vehicle is inan idle mode. If the vehicle is not in an idle mode, the method mayinclude causing a temperature control subsystem of the vehicle toinitiate a heating cycle to heat the sensor. Initiation of the heatingcycle may include turning on of the temperature control subsystem,increasing the heating efficiency of the temperature control subsystem,and/or decreasing the cooling efficiency of the temperature controlsubsystem. Optionally, the method may also include determining whetherthe current temperature of the sensor is less than a second thresholdtemperature. If the current temperature is less than the secondthreshold temperature, the sensor cleaning subsystem may heat thecleaning fluid, and initiate a cleaning cycle and direct the heatedcleaning fluid to the sensor to heat the sensor. The second thresholdtemperature may be less than the first threshold temperature.Optionally, the system may first determine whether the vehicle is in asafe to clean mode, and initiate the cleaning cycle only in response todetermining that the vehicle is in a safe to clean mode.

In one or more embodiments, the method may also include stopping thecleaning cycle after a pre-determined time period, in response todetermining that the current temperature of the sensor is less than thefirst threshold temperature, receipt of user instructions, in responseto determining that it is unsafe to continue the cleaning cycle and/orat the end of an idle mode of the vehicle.

In some embodiments, cleaning fluid may be heated using thermal energyobtained from waste thermal energy generated by an engine of thevehicle, thermal energy used in a cabin of the vehicle, and/or adedicated thermal energy source for heating the cleaning fluid.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example system for controlling the temperature ofa sensor in a vehicle.

FIG. 2 illustrates an example method of controlling the temperature ofone or more sensors in a vehicle.

FIG. 3 illustrates an example method of controlling the temperature ofone or more sensors in a vehicle.

FIG. 4 illustrates another example method of controlling the temperatureof one or more sensors in a vehicle.

FIG. 5 illustrates an example method of controlling the temperature ofone or more sensors in a vehicle.

FIG. 6 is a block diagram of elements of a computing device on which thevarious systems and methods in this document could be implemented.

DETAILED DESCRIPTION

As used in this document, the singular forms “a,” “an,” and “the”include plural references unless the context clearly dictates otherwise.Unless defined otherwise, all technical and scientific terms used hereinhave the same meanings as commonly understood by one of ordinary skillin the art. As used in this document, the term “comprising” means“including, but not limited to.”

Furthermore, the term “about,” as used herein when referring to ameasurable value such as time, temperature, volume or the like, is meantto encompass any normal fluctuations appreciated by one of ordinaryskill in the relevant art.

Various embodiments of the present disclosure will be described belowwith reference to the drawings constituting a part of the description.It should be understood that, although terms representing directions areused in the present disclosure, such as “front”, “rear”, “upper”,“lower”, “left”, “right”, and the like, for describing various examplestructural parts and elements of the present disclosure, these terms areused herein only for the purpose of convenience of explanation and aredetermined based on the example orientations shown in the drawings.Since the embodiments disclosed by the present disclosure can bearranged according to different directions, these terms representingdirections are merely used for illustration and should not be regardedas limitation. Wherever possible, the same or similar reference marksused in the present disclosure refer to the same components.

In this document, the terms “processor” and “processing device” refer toa hardware component of an electronic device that is configured toexecute programming instructions. Except where specifically statedotherwise, the singular term “processor” or “processing device” isintended to include both single-processing device embodiments andembodiments in which multiple processing devices together orcollectively perform a process.

A “vehicle”, as used herein, refers to any moving form of conveyancethat is capable of carrying either one or more human occupants and/orcargo and is powered by any form of energy. The term “vehicle” includes,but is not limited to: cars, trucks, vans, minivan, trains, autonomousvehicles, flying robotic machines, or the like.

FIG. 1 is a block diagram illustrating an example system 100 thatincludes a vehicle 101. While this application describes the sensor asbeing installed on a vehicle by way of example, the system (andassociated methods) may be used on other equipment that has sensors suchas, without limitation, manufacturing equipment, monitoring systems, orother sensor-equipped devices. In some embodiments, the vehicle 101includes a controller 110, one or more sensors 112, one or moretemperature monitors 113 configured to collect temperature datacorresponding to the one or more sensors 112, a sensor cleaningsubsystem 120. In some embodiments, the vehicle 101 may also include atemperature control subsystem(s) 130.

When used on a vehicle, the one or more sensors 112 may be configured tocollect data relating to various components or conditions of the vehicle101. Examples of vehicle components include, without limitations, abraking system, a steering system, a powertrain, etc. Examples ofvehicle conditions include, without limitations, speed, acceleration,pitch, yaw, roll, etc. Examples of sensors may include, withoutlimitation, cameras, temperature sensors, position sensors, locationsensors, fuel sensors, motion sensors, global positioning system (GPS),humidity sensors, occupancy sensors, or the like. The sensors 110 may belocated on the outside of the vehicle 101 and/or inside the vehicle 101.Each of the one or more sensors has an operational temperature rangewithin which the sensor operates reliably and/or that improves thelifespan of the sensor. For example, certain sensors in a vehicle mayhave an operational temperature range of about −40° C. to about 85° C.

In certain embodiments, the one or more temperature monitors 113 may beconfigured to collect temperature data corresponding to the one or moresensors 112 and transmit the collected data to the controller 110. In anembodiment, each of the one or more sensors 112 may be associated withand/or include a temperature monitor. Alternatively and/or additionally,a plurality of the one or more sensors 112 may be associated with asingle temperature monitor. For example, a temperature monitor may beconfigured to collect temperature data in the vicinity of collection ofsensors that are placed close to each other within the vehicle 101.Examples of the temperature monitors may include any now or hereafterknown temperature sensors such as, without limitation, thermistors,thermocouples, semiconductor-based temperature sensors, resistancetemperature detectors, or the like.

The vehicle 101 may also include a sensor cleaning subsystem 120including a cleaning fluid reservoir 121 configured to hold a cleaningfluid. The cleaning fluid reservoir may be in fluid communication withone or more ejection ports 123 via at least one fluid pump 124. Thefluid pump 124 may be configured to control the flow rate and pressureof fluid flow from the cleaning fluid reservoir 121 to the one or moreejection ports 123. The one or more ejection ports 123 may be disposedproximate to each of the one or more sensors 112, and may receive thecleaning fluid from the cleaning fluid reservoir 121 via one or morecontrol valves 122. In certain embodiments, the one or more controlvalves 122 are configured to direct and control the flow of cleaningfluid towards a subset of the one or more sensors 112 upon receipt ofinstructions from the controller 110. For example, a control valve maybe open, close, partially open, or the like, in order to allow, stop, orotherwise volumetrically control the flow of the cleaning fluid towardsa sensor. The ejection ports 123 may be positioned to (and/or mayinclude a fluid delivery device configured to) deliver cleaning fluidaround and/or to the surface of the corresponding sensor and/or sensorbody. Example may include, without limitation, nozzles, sprays, or thelike. In certain embodiments, a brush or other mechanical cleaningdevice may associated with the ejection ports 123 to effect mechanicalcleaning of a sensor.

The cleaning fluid may be a variety of known substances that can cleandirt, debris, etc. from the one or more sensors and also have a coolingeffect on objects that come in contact with the cleaning fluid. Forexample, the cleaning fluid may have a boiling temperature that is belowand/or close to the upper threshold of the operational temperature rangeof the one or more sensors and that is suitable to clean dirt, debris,etc. from the one or more sensors. For example, the cleaning fluid maybe a mixture including, in part, methanol and water that has a boilingtemperature of about 65° C., when the operational temperature range ofthe one or more sensors is about 85° C. Having a boiling point that isless than that of pure water allows for triggering of evaporation at alower temperature and thus helps in removal of heat from a sensor. Otherexamples of the cleaning fluid may include, without limitation, water,organic solvents, inorganic solvents, glycol mixtures, ethanol mixtures,isopropyl alcohol mixtures, ammonia mixtures, or any other washerfluids.

On the other hand, if the cleaning fluid is used for heating of asensor, the cleaning fluid may have properties such as freezing pointbelow the lower operational range of the sensor, or the like. It will beunderstood to those skilled in the art that the composition and/orrelative percentages of one or more components of the cleaning fluid mayvary depending on whether the cleaning fluid may be used for cooling asensor or heating a sensor.

In some embodiments, the controller 110 may include a processor that isconfigured to control at least some of the operations of the sensorcleaning subsystem 120 and/or the temperature control subsystem(s) 130,as described below in more detail. In an embodiment, controller 110 maycontrol at least some of the operations of the sensor cleaning subsystem120 and/or the temperature control subsystem(s) 130 based on datareceived from the one or more sensors 112 and/or the one or moretemperature monitors 113. The controllers described herein may bemicrocontrollers or any other suitable type controller.

Controllers of prior art vehicle systems are configured to control theflow of cleaning liquid towards a sensor of a vehicle in relation to acleaning operation only. For example, the prior art controllers maydirect the cleaning liquid towards a sensor periodically, upon receivinga signal that the sensor needs cleaning (for e.g., when images obtainedby a camera sensors a blurry, a sensor is malfunctioning, etc.), and/oruser instructions. Alternatively, the prior art controllers may stop theflow of cleaning liquid towards a sensor if the sensor is clean, thevehicle is moving at high speeds, or the like. However, the currentdisclosure describes the use of existing sensor cleaning subsystems forcooling one or more sensors of the vehicle based on their operationaltemperature ranges.

In an embodiment, the vehicle 101 further includes one or moretemperature control subsystem(s) 130 for each sensor or a group ofsensors. The temperature control subsystem(s) 130 may be any now orhereafter known sensor temperature control systems configured to controlthe temperature of a sensor and/or a group of sensors (e.g., located ina particular vehicle region) using, for example, air based temperaturecontrol. It will be understood to those skilled in the art thatoperations of the temperature control subsystem(s) 130 and the sensorcleaning subsystem 120 to control the temperature of one or more sensorsof the vehicle 101 are not correlated with each other. In other words,the temperature control subsystem(s) 130 and the sensor cleaningsubsystem 120 may control the temperature of one or more sensors of thevehicle 101 in conjunction with each other and/or in the absence ofoperation of the other.

In certain embodiments, the one or more temperature control subsystem(s)130 may also include temperature control system that control the ambienttemperature of the interior of the vehicle 101. Examples may include,without limitation, vehicle automotive heating, ventilation, and airconditioning (HVAC) system, air flow system, or the like.

FIG. 2 is a flowchart in accordance with various embodimentsillustrating and describing an example method of controlling thetemperature of one or more sensors of a vehicle (cooling effect). Whilethe method 200 is described for the sake of convenience and not with anintent of limiting the disclosure as comprising a series and/or a numberof steps, it is to be understood that the process does not need to beperformed as a series of steps and/or the steps do not need to beperformed in the order shown and described with respect to FIG. 2 butthe process may be integrated and/or one or more steps may be performedtogether, simultaneously, or the steps may be performed in the orderdisclosed or in an alternate order. Likewise, one or more stepsdescribed below need not be performed.

At 202, the system collects temperature data corresponding to each ofthe one or more sensors. In an embodiment, the temperature data may betemperature of a sensor. Alternatively and/or additionally, thetemperature data may be temperature of the proximate area around asensor. The system may start collecting temperature data periodicallyafter a triggering event. Examples of the triggering event may include,without limitation, activation of a sensor, ignition of the vehicleengine, detection of an occupant in the vehicle, environmentaltemperature outside the vehicle over a threshold temperature, ambienttemperature inside the vehicle over a threshold temperature, an eventindicating that the vehicle will be started within a certain timeinterval (e.g., in response to a transaction with a passenger requestinga ride in the vehicle using a ride-share app), unlocking of the vehicle,vehicle driver information (e.g., schedules, habits, or the like),presence of the vehicle key within a predetermined distance of thevehicle, user instructions, etc. or a combination thereof.

At 204, the system may determine whether the temperature correspondingto the sensor is greater than or equal to a threshold temperature (T).In an embodiment, the system may analyze the collected temperature datacorresponding to the sensor and/or in the vicinity of the sensor todetermine if the temperature of the sensor is greater than or equal tothe threshold temperature (T). The threshold temperature (T) may be atemperature that is less than or equal to the upper bounds of theoperational temperature range of the sensor. Alternatively, thethreshold temperature may be a temperature less than or equal to atemperature at which the sensor will start to malfunction. If thetemperature is less than T (204: NO), the system may continue collectingtemperature data (i.e., step 202).

If the temperature is greater than or equal to T (204: NO), the systemmay at 206 determine whether it is safe to initiate a cleaning cycle.The system may determine if it safe to initiate the cleaning cycle basedon a rule set that includes rules specifying that it is unsafe toinitiate the cleaning cycle upon occurrence of one or more conditions.Examples of such conditions may include, without limitation, discomfortto the passengers of the vehicle, creation of hazardous conditionsbecause of sensor cleaning (e.g., obstruction of driver view through thewindshield, driver distraction when the vehicle starts moving if it is amanned vehicle, obstruction of sensor functioning, etc.), high trafficarea, vehicle moving at high speeds, hazardous weather conditions,vehicle movement at any speed during cleaning cycle, or the like.Additionally and/or alternatively, the rule set may include rulesidentifying conditions that are determined to be safe for initiation thecleaning cycle such as, without location, location of the vehicle, speedof the vehicle, occupancy of the vehicle, type or location of thesensor, weather conditions time of the day, or the like, such thatinitiation of a cleaning cycle does not compromise the data collected bya sensor and/or may lead to a hazardous condition (e.g., accident). Theinclusion of one or more of the above conditions in the rule set maydepend on, without limitation, position of the sensor in the vehicle,type of the sensor, whether or not the vehicle is moving, anticipatedstart time of vehicle movement, position of vehicle passengers in thevehicle, etc. For example, if the sensor is a camera sensor for whichintegrity of the data collected will be compromised if cleaning fluid issprayed on the camera sensor, the rule set may include a rule that it isunsafe to clean the sensor whenever the vehicle is moving. Hence, thesystem may determine that it is not safe to initiate the cleaning cycleif the vehicle is moving and/or is going to start moving during thecleaning cycle. Similarly, for a manned vehicle, if the sensor islocated on or near the windshield, the rule set may include a rule thatit is unsafe to clean the sensor whenever the vehicle is moving. Hence,the system may determine that it is not safe to initiate the cleaningcycle if the vehicle is moving and/or is going to start moving duringthe cleaning cycle. Similarly, if a sensor is critical to navigatingthrough a high traffic area (e.g., blind spot sensor), the rule set mayinclude a rule that it is unsafe to clean the sensor whenever thevehicle is in a high traffic area and/or is anticipated to be in a hightraffic area (based on, for example, the navigation system data).

The system may make the determination of whether or not it is safe toinitiate a cleaning cycle based on data obtained from one or moresensors of the vehicle.

If the system determines that it is not safe to initiate a cleaningcycle (206: NO), it may cause the sensor to stop functioning (i.e., turnoff) in order to prevent sensor malfunction and/or breakdown (212).Alternatively, the system may not turn off the sensor if the sensorfunctioning is critical to the operation of the vehicle and sensormalfunction is acceptable. In another embodiment, the system may eitherinitiate a cooling cycle using the temperature control subsystem of thatsensor and/or increase the cooling effect of the temperature controlsubsystem, if it is already turned on (e.g., by increasing fan speed).

However, if the system determines that it is safe to initiate a cleaningcycle (206: YES), the system may cause the sensor cleaning subsystem ofthe vehicle to initiate a cleaning cycle (208) for the sensor. In anembodiment, initiation of a cleaning cycle causes the controller tooperate one or more valves (i.e., open and/or close) of the cleaningsubsystem to direct cleaning fluid from the cleaning fluid reservoirtowards the sensor. The controller may control the flow rate and/orfluid pressure via a pump. As discussed above, the cleaning fluid has acooling effect and may bring down the temperature of the sensor withinits normal operational range.

At 210, the system may cause the cleaning subsystem to stop the cleaningcycle. In an embodiment, stopping the cleaning cycle causes thecontroller to operate one or more valves (i.e., open and/or close) ofthe cleaning subsystem to stop the flow of cleaning fluid from thecleaning fluid reservoir towards the sensor. The system may stop thecleaning cycle upon occurrence of one or more of the following: receiptof user instructions to stop the cleaning cycle, after a certain periodof time, based on temperature data corresponding to the sensor (e.g., ifthe temperature is at least a pre-defined value below T, determiningthat it unsafe to continue the cleaning cycle (based on the rule setdescribed above in step 208 with respect to unsafe conditions), etc. Thepre-defined temperature value below T may be determined by taking intoaccount that the cleaning fluid needs some time to cool down the sensor(i.e., cooling is not immediate).

Furthermore, in certain embodiment, the system may continue monitoringthe temperature of the sensor after stopping of the cleaning cycle andmay cause the sensor to stop functioning (i.e., turn off) in order toprevent sensor malfunction and/or breakdown if the temperature is stillgreater than or equal to T. Alternatively, the system may let the sensormalfunction.

FIG. 3 is a flowchart in accordance with various embodimentsillustrating and describing an example method of controlling thetemperature of one or more sensors of a vehicle (cooling effect). Whilethe method 300 is described for the sake of convenience and not with anintent of limiting the disclosure as comprising a series and/or a numberof steps, it is to be understood that the process does not need to beperformed as a series of steps and/or the steps do not need to beperformed in the order shown and described with respect to FIG. 3 butthe process may be integrated and/or one or more steps may be performedtogether, simultaneously, or the steps may be performed in the orderdisclosed or in an alternate order. Likewise, one or more stepsdescribed below need not be performed.

At 302, the system collects temperature data corresponding to each ofthe one or more sensors. In an embodiment, the temperature data may betemperature of a sensor. Alternatively and/or additionally, thetemperature data may be temperature of the proximate area around asensor. The system may start collecting temperature data periodicallyafter a triggering event. Examples of the triggering event may include,without limitation, activation of a sensor, ignition of the vehicleengine, detection of an occupant in the vehicle, environmentaltemperature outside the vehicle over a threshold temperature, ambienttemperature inside the vehicle over a threshold temperature, an eventindicating that the vehicle will be started within a certain timeinterval (e.g., in response to a transaction with a passenger requestinga ride in the vehicle using a ride-share app), unlocking of the vehicle,vehicle driver information (e.g., schedules, habits, or the like),presence of the vehicle key within a predetermined distance of thevehicle, user instructions, etc. or a combination thereof.

At 304, the system may determine whether the temperature correspondingto the sensor is greater than or equal to a first threshold temperature(T1). In an embodiment, the system may analyze the collected temperaturedata corresponding to the sensor and/or in the vicinity of the sensor todetermine if the temperature of the sensor is greater than or equal tothe first threshold temperature (T1). The first threshold temperature(T1) may be a temperature that is less than or equal to the upper boundsof the operational temperature range of the sensor. Alternatively, thefirst threshold temperature may be a temperature less than or equal towhich the sensor will start to malfunction. If the temperature is lessthan T1 (304: NO), the system may continue collecting temperature data(i.e., step 302).

If the system determines that the temperature corresponding to thesensor is greater than or equal T1 (304: YES), the system may thendetermine whether the vehicle is an idle (or standby or low power mode)mode (306). In an embodiment, an idle mode of a vehicle may correspondto the vehicle being in one or more of the following states: the vehicleengine is on but the vehicle is not moving or has been stationary for acertain amount of time (for e.g., stalled in traffic, waiting for apassenger, etc.); when the vehicle engine will be turned on within athreshold period of time; when the vehicle will start moving within athreshold period of time; when the vehicle key is within a predeterminedrange of the vehicle but the engine is not on and/or the vehicle is notmoving; when there is an occupant in the vehicle but the vehicle isstationary and/or the engine is not on; unlocking of the vehicle beforethe vehicle starts moving, etc., or a combination thereof. The systemmay determine that that vehicle engine will be turned on and/or thevehicle will start moving within a threshold period of time based on,for example, driver information (e.g., if a driver uses the vehicle ataround the same time on most weekdays to commute), vehicle schedule(e.g., if the vehicle is an autonomous vehicle), in response tocompletion of a transaction with a passenger requesting a ride in thevehicle, in response to receiving a request for a job for the vehicle(e.g., for a construction vehicle, an emergency call for an emergencyvehicle), in response to determining that the traffic is going to reduceif the vehicle is stalled in traffic (e.g., based on GPS data), or thelike, or a combination thereof. Vehicles such as, without limitation,police vehicles, emergency responder vehicles, taxis, ride-sharevehicles, construction and utility vehicles, etc. often spend prolongedperiods of time in an idle or standby mode.

The system may also make the determination of whether or not the vehicleis an idle mode based on data obtained from one or more sensors of thevehicle and/or based on lack of data from the sensors (if the sensorsare not activated in an idle state).

If the system determines that the vehicle is not in an idle mode (306:NO), the system may cause the temperature control subsystem associatedwith the sensor to initiate a cooling cycle (316) (for example, toinitiate air-based cooling). Initiation of the cooling cycle may includeturning on the temperature control subsystem and/or increasing itscooling effect if the temperature control subsystem is already on (e.g.,by increasing the fan speed).

In certain embodiments, the temperature control subsystem is first usedto cool down the sensor to conserve cleaning fluid and/or to preservesensor data integrity, and the cleaning cycle is initiated when thetemperature control subsystem cannot handle the cooling by itself and/orin a given time, as discussed below.

The system may continue monitoring the temperature of the sensor afterinitiation of the cooling cycle. At 318, the system may determinewhether the temperature of the sensor is greater than or equal to asecond threshold temperature (T2). In an embodiment, the secondthreshold temperature (T2) greater than T1, and is a temperature overwhich the temperature control subsystem cannot handle the cooling byitself and/or in a given time. If the temperature of the sensor is lessthan T2 (318: NO), the system may determine (320) whether thetemperature of the sensor is less than a third threshold temperature(T3). In an embodiment, the third threshold temperature (T3) is atemperature below which no or reduced cooling action is required for thesensor. If the temperature of the sensor is less than T3 (320: YES), thesystem stops the cooling cycle (322). In an embodiment, stopping thecooling cycle may include turning off the temperature control subsystemand/or reducing the cooling effect of the temperature control subsystem.

However, if the temperature of the sensor is greater than or equal to T3(320: NO), the system continues performing steps 316-320.

If the temperature of the sensor is greater than or equal to T2 (318:YES) and/or ff the system determines that the vehicle is in an idle mode(306: YES), the system may perform steps 308-314, as discussed below.

At 308, the system may determine whether it is safe to initiate acleaning cycle. The system may determine if it safe to initiate thecleaning cycle based on a rule set that includes rules specifying thatit is unsafe to initiate the cleaning cycle upon occurrence of one ormore conditions. Examples of such conditions may include, withoutlimitation, discomfort to the passengers of the vehicle, creation ofhazardous conditions because of sensor cleaning (e.g., obstruction ofdriver view through the windshield, driver distraction when the vehiclestarts moving if it is a manned vehicle, obstruction of sensorfunctioning, etc.), high traffic area, vehicle moving at high speeds,hazardous weather conditions, vehicle movement at any speed duringcleaning cycle, or the like. Additionally and/or alternatively, the ruleset may include rules identifying conditions that are determined to besafe for initiation the cleaning cycle such as, without location,location of the vehicle, speed of the vehicle, occupancy of the vehicle,type or location of the sensor, weather conditions time of the day, orthe like, such that initiation of a cleaning cycle does not compromisethe data collected by a sensor. The inclusion of one or more of theabove conditions in the rule set may depend on, without limitation,position of the sensor in the vehicle, type of the sensor, whether ornot the vehicle is moving, anticipated start time of vehicle movement,position of vehicle passengers in the vehicle, etc. For example, if thesensor is a camera sensor for which integrity of the data collected willbe compromised if cleaning fluid is sprayed on the camera sensor, therule set may include a rule that it is unsafe to clean the sensorwhenever the vehicle is moving. Hence, the system may determine that itis not safe to initiate the cleaning cycle if the vehicle is movingand/or is going to start moving during the cleaning cycle. Similarly,for a manned vehicle, if the sensor is located on or near thewindshield, the rule set may include a rule that it is unsafe to cleanthe sensor whenever the vehicle is moving. Hence, the system maydetermine that it is not safe to initiate the cleaning cycle if thevehicle is moving and/or is going to start moving during the cleaningcycle. Similarly, if a sensor is critical to navigating through a hightraffic area (e.g., blind spot sensor), the rule set may include a rulethat it is unsafe to clean the sensor whenever the vehicle is in a hightraffic area and/or is anticipated to be in a high traffic area (basedon, for example, the navigation system data).

The system may make the determination of whether or not it is safe toinitiate a cleaning cycle based on data obtained from one or moresensors of the vehicle.

If the system determines that it is not safe to initiate a cleaningcycle (308: NO), it may cause the sensor to stop functioning (i.e., turnoff) in order to prevent sensor malfunction and/or breakdown (314).Alternatively, the system may not turn off the sensor if the sensorfunctioning is critical to the operation of the vehicle and sensormalfunction is acceptable. In another embodiment, the system may eitherinitiate a cooling cycle using the temperature control subsystem of thatsensor or increase the cooling effect of the temperature controlsubsystem, if it is already turned on (e.g., by increasing fan speed).

However, if the system determines that it is safe to initiate a cleaningcycle (308: YES), the system may cause the sensor cleaning subsystem ofthe vehicle to initiate a cleaning cycle (310) for the sensor. In anembodiment, initiation of a cleaning cycle causes the controller tooperate one or more valves (i.e., open and/or close) of the cleaningsubsystem to direct cleaning fluid from the cleaning fluid reservoirtowards the sensor. The controller may control the flow rate and/orfluid pressure via a pump. As discussed above, the cleaning fluid has acooling effect and may bring down the temperature of the sensor withinits normal operational range.

In certain embodiments, the cooling cycle may be stopped (if turned onin a non-idle mode) when the cleaning cycle is turned on. Alternatively,the cooling cycle may be executed in association with the cleaning cycleto, for example, cool down the sensor in a shorter time.

At 312, the system may cause the cleaning subsystem to stop the cleaningcycle. In an embodiment, stopping the cleaning cycle causes thecontroller to operate one or more valves (i.e., open and/or close) ofthe cleaning subsystem to stop the flow of cleaning fluid from thecleaning fluid reservoir towards the sensor. The system may stop thecleaning cycle upon occurrence of one or more of the following: receiptof user instructions to stop the cleaning cycle, after a certain periodof time, based on temperature data corresponding to the sensor (e.g., ifthe temperature is at least a pre-defined value below T1 if the vehicleis in idle mode, if the temperature is at least a pre-defined valuebelow T2 if the vehicle is not in idle mode, or the like), determiningthat it unsafe to continue the cleaning cycle (based on the rule setdescribed above in step 308 with respect to unsafe conditions), or upondetermining that the vehicle in not in an idle mode. The pre-definedtemperature value below T2 may be a temperature value at which theprimary temperature control sub-system may be able to cool down thesensor by itself. The pre-defined temperature value below T2 may bedetermined by taking into account that the cleaning fluid needs sometime to cool down the sensor (i.e., cooling is not immediate).

Furthermore, in certain embodiment, the system may continue monitoringthe temperature of the sensor after stopping of the cleaning cycle andmay cause the sensor to stop functioning (i.e., turn off) in order toprevent sensor malfunction and/or breakdown if the temperature is stillgreater than or equal to T1 (or T1 plus the hysteresis temperature).Alternatively, the system may let the sensor malfunction.

In certain embodiments, before initiating the cleaning cycle, the systemmay determine whether the ambient temperature (i.e., the temperature ofthe environment of the vehicle) is above an ambient temperaturethreshold. If the system determines that the ambient temperature isabove the ambient temperature threshold, the system may turn on avehicle interior temperature control system (e.g., HVAC system of thevehicle) and/or increase its cooling effect if already on (e.g., byincreasing the fan speed) before initiating the cleaning cycle to cooldown the interior of the vehicle as well as the sensor.

FIG. 4 is a flowchart in accordance with various embodimentsillustrating and describing an example method of using the sensorcleaning subsystem of a vehicle to control the temperature of one ormore sensors (heating effect). While the method 400 is described for thesake of convenience and not with an intent of limiting the disclosure ascomprising a series and/or a number of steps, it is to be understoodthat the process does not need to be performed as a series of stepsand/or the steps do not need to be performed in the order shown anddescribed with respect to FIG. 4 but the process may be integratedand/or one or more steps may be performed together, simultaneously, orthe steps may be performed in the order disclosed or in an alternateorder. Likewise, one or more steps described below need not beperformed.

At 402, the system collects temperature data corresponding to each ofthe one or more sensors. In an embodiment, the temperature data may betemperature of a sensor. Alternatively and/or additionally, thetemperature data may be temperature of the proximate area around asensor. The system may start collecting temperature data periodicallyafter a triggering event. Examples of the triggering event may include,without limitation, activation of a sensor, ignition of the vehicleengine, detection of an occupant in the vehicle, environmentaltemperature outside the vehicle below a threshold temperature, ambienttemperature inside the vehicle below a threshold temperature, an eventindicating that the vehicle will be started within a certain timeinterval (e.g., in response to a transaction with a passenger requestinga ride in the vehicle using a ride-share app), unlocking of the vehicle,vehicle driver information (e.g., schedules, habits, or the like),presence of the vehicle key within a predetermined distance of thevehicle, user instructions, etc. or a combination thereof.

At 404, the system may determine whether the temperature correspondingto the sensor is less than or equal to a threshold temperature (T). Inan embodiment, the system may analyze the collected temperature datacorresponding to the sensor and/or in the vicinity of the sensor todetermine if the temperature of the sensor is less than or equal to thethreshold temperature (T). The threshold temperature (T) may be atemperature that is greater than or equal to the lower bounds of theoperational temperature range of the sensor. Alternatively, thethreshold temperature may be a temperature greater than or equal to atemperature at which the sensor will start to malfunction. If thetemperature is greater than T (404: NO), the system may continuecollecting temperature data (i.e., step 402).

If the temperature is less than or equal to T (404: NO), the system mayat 406 determine whether it is safe to initiate a cleaning cycle. Thesystem may determine if it safe to initiate the cleaning cycle based ona rule set that includes rules specifying that it is unsafe to initiatethe cleaning cycle upon occurrence of one or more conditions. Examplesof such conditions may include, without limitation, discomfort to thepassengers of the vehicle, creation of hazardous conditions because ofsensor cleaning (e.g., obstruction of driver view through thewindshield, driver distraction when the vehicle starts moving if it is amanned vehicle, obstruction of sensor functioning, etc.), high trafficarea, vehicle moving at high speeds, hazardous weather conditions,vehicle movement at any speed during cleaning cycle, or the like.Additionally and/or alternatively, the rule set may include rulesidentifying conditions that are determined to be safe for initiation thecleaning cycle such as, without location, location of the vehicle, speedof the vehicle, occupancy of the vehicle, type or location of thesensor, weather conditions time of the day, or the like, such thatinitiation of a cleaning cycle does not compromise the data collected bya sensor and/or may lead to a hazardous condition (e.g., accident). Theinclusion of one or more of the above conditions in the rule set maydepend on, without limitation, position of the sensor in the vehicle,type of the sensor, whether or not the vehicle is moving, anticipatedstart time of vehicle movement, position of vehicle passengers in thevehicle, etc. For example, if the sensor is a camera sensor for whichintegrity of the data collected will be compromised if cleaning fluid issprayed on the camera sensor, the rule set may include a rule that it isunsafe to clean the sensor whenever the vehicle is moving. Hence, thesystem may determine that it is not safe to initiate the cleaning cycleif the vehicle is moving and/or is going to start moving during thecleaning cycle. Similarly, for a manned vehicle, if the sensor islocated on or near the windshield, the rule set may include a rule thatit is unsafe to clean the sensor whenever the vehicle is moving. Hence,the system may determine that it is not safe to initiate the cleaningcycle if the vehicle is moving and/or is going to start moving duringthe cleaning cycle. Similarly, if a sensor is critical to navigatingthrough a high traffic area (e.g., blind spot sensor), the rule set mayinclude a rule that it is unsafe to clean the sensor whenever thevehicle is in a high traffic area and/or is anticipated to be in a hightraffic area (based on, for example, the navigation system data).

The system may make the determination of whether or not it is safe toinitiate a cleaning cycle based on data obtained from one or moresensors of the vehicle.

If the system determines that it is not safe to initiate a cleaningcycle (406: NO), it may cause the sensor to stop functioning (i.e., turnoff) in order to prevent sensor malfunction and/or breakdown (414).Alternatively, the system may not turn off the sensor if the sensorfunctioning is critical to the operation of the vehicle and sensormalfunction is acceptable. In another embodiment, the system may eitherinitiate a heating cycle using the temperature control subsystem of thatsensor and/or increase the heating effect of the temperature controlsubsystem, if it is already turned on (e.g., by increasing fan speed ifhot air is being circulated by the temperature control subsystem, bydecreasing the fan speed if cold air is being circulated by thetemperature control subsystem, etc.).

However, if the system determines that it is safe to initiate a cleaningcycle (408: YES), the system may cause a fluid heater to heat thecleaning fluid (410), and the sensor cleaning subsystem of the vehicleto initiate a cleaning cycle (412) for the sensor using the heatedcleaning fluid. The fluid heater may receive thermal energy for heatingthe cleaning fluid from a dedicated thermal energy source (e.g., aheater), waste heat generated by the engine (e.g., power train), and/orheat generated inside the vehicle cabin.

In an embodiment, initiation of a cleaning cycle causes the controllerto operate one or more valves (i.e., open and/or close) of the cleaningsubsystem to direct heated cleaning fluid from the cleaning fluidreservoir towards the sensor. The controller may control the flow rateand/or fluid pressure via a pump. In certain embodiment, the cleaningfluid is heated in the cleaning fluid reservoir itself. Alternativelyand/or additionally, a heater is configured to heat the cleaning fluidin a different reservoir. The heated cleaning fluid may bring up thetemperature of the sensor within its normal operational range.

At 412, the system may cause the cleaning subsystem to stop the cleaningcycle. In an embodiment, stopping the cleaning cycle causes thecontroller to operate one or more valves (i.e., open and/or close) ofthe cleaning subsystem to stop the flow of cleaning fluid from thecleaning fluid reservoir towards the sensor. The system may stop thecleaning cycle upon occurrence of one or more of the following: receiptof user instructions to stop the cleaning cycle, after a certain periodof time, based on temperature data corresponding to the sensor (e.g., ifthe temperature is at least a pre-defined value above T, determiningthat it unsafe to continue the cleaning cycle (based on the rule setdescribed above in step 408 with respect to unsafe conditions), etc. Thepre-defined temperature value above T may be determined by taking intoaccount that the cleaning fluid needs some time to heat the sensor(i.e., heating is not immediate).

Furthermore, in certain embodiment, the system may continue monitoringthe temperature of the sensor after stopping of the cleaning cycle andmay cause the sensor to stop functioning (i.e., turn off) in order toprevent sensor malfunction and/or breakdown if the temperature is stillless than or equal to T. Alternatively, the system may let the sensormalfunction.

FIG. 5 is a flowchart in accordance with various embodimentsillustrating and describing an example method of using the sensorcleaning subsystem of a vehicle to control the temperature of one ormore sensors (heating effect). While the method 500 is described for thesake of convenience and not with an intent of limiting the disclosure ascomprising a series and/or a number of steps, it is to be understoodthat the process does not need to be performed as a series of stepsand/or the steps do not need to be performed in the order shown anddescribed with respect to FIG. 5 but the process may be integratedand/or one or more steps may be performed together, simultaneously, orthe steps may be performed in the order disclosed or in an alternateorder. Likewise, one or more steps described below need not beperformed.

At 502, the system collects temperature data corresponding to each ofthe one or more sensors. In an embodiment, the temperature data may betemperature of a sensor. Alternatively and/or additionally, thetemperature data may be temperature of the proximate area around asensor. The system may start collecting temperature data periodicallyafter a triggering event. Examples of the triggering event may include,without limitation, activation of a sensor, ignition of the vehicleengine, detection of an occupant in the vehicle, environmentaltemperature outside the vehicle below a threshold temperature, ambienttemperature inside the vehicle below a threshold temperature, an eventindicating that the vehicle will be started within a certain timeinterval (e.g., in response to a transaction with a passenger requestinga ride in the vehicle using a ride-share app), unlocking of the vehicle,vehicle driver information (e.g., schedules, habits, or the like),presence of the vehicle key within a predetermined distance of thevehicle, user instructions, etc. or a combination thereof.

At 504, the system may determine whether the temperature correspondingto the sensor is less than or equal to a first threshold temperature(T1). In an embodiment, the system may analyze the collected temperaturedata corresponding to the sensor and/or in the vicinity of the sensor todetermine if the temperature of the sensor is less than or equal to thefirst threshold temperature (T1). The first threshold temperature (T1)may be a temperature that is greater than or equal to the lower boundsof the operational temperature range of the sensor and/or greater thanor equal to which the sensor will start to malfunction (e.g., if thesensor stops functioning at about −40° C., T1 may be about −30° C.). Ifthe temperature is greater than T1 (505: NO), the system may continuecollecting temperature data (i.e., step 502).

If the system determines that the temperature corresponding to thesensor is less than or equal T1 (505: YES), the system may thendetermine whether the vehicle is an idle (or standby or low power mode)mode (506). In an embodiment, an idle mode of a vehicle may correspondto the vehicle being in one or more of the following states: the vehicleengine is on but the vehicle is not moving or has been stationary for acertain amount of time (for e.g., stalled in traffic, waiting for apassenger, etc.); when the vehicle engine will be turned on within athreshold period of time; when the vehicle will start moving within athreshold period of time; when the vehicle key is within a predeterminedrange of the vehicle but the engine is not on and/or the vehicle is notmoving; when there is an occupant in the vehicle but the vehicle isstationary and/or the engine is not on; unlocking of the vehicle beforethe vehicle starts moving, etc., or a combination thereof. The systemmay determine that that vehicle engine will be turned on and/or thevehicle will start moving within a threshold period of time based on,for example, driver information (e.g., if a driver uses the vehicle ataround the same time on most weekdays to commute), vehicle schedule(e.g., if the vehicle is an autonomous vehicle), in response tocompletion of a transaction with a passenger requesting a ride in thevehicle, in response to receiving a request for a job for the vehicle(e.g., for a construction vehicle, an emergency call for an emergencyvehicle), in response to determining that the traffic is going to reduceif the vehicle is stalled in traffic (e.g., based on GPS data), or thelike, or a combination thereof. Vehicles such as, without limitation,police vehicles, emergency responder vehicles, taxis, ride-sharevehicles, construction and utility vehicles, etc. often spend prolongedperiods of time in an idle or standby mode.

The system may also make the determination of whether or not the vehicleis an idle mode based on data obtained from one or more sensors of thevehicle and/or based on lack of data from the sensors (if the sensorsare not activated in an idle state).

If the system determines that the vehicle is not in an idle mode (506:NO), the system the system may cause the temperature control subsystemassociated with the sensor to initiate a heating cycle (518) (forexample, blowing hot air over the sensor). Initiation of the heatingcycle may include turning on the temperature control subsystem and/orincreasing its heating effect if the temperature control subsystem isalready on (e.g., by increasing the fan speed or temperature of air if afan is blowing hot air, lowering the fan speed if the fan is blowingcold air, etc.).

In certain embodiments, temperature control subsystem may be used toheat the sensor to conserve cleaning fluid and/or to preserve sensordata integrity, and the cleaning cycle is initiated when the temperaturecontrol subsystem cannot handle the heating by itself and/or in a giventime, as discussed below.

The system may continue monitoring the temperature of the sensor afterinitiation of the heating cycle. At 520, the system may determinewhether the temperature of the sensor is less than or equal to a secondthreshold temperature (T2). In an embodiment, the second thresholdtemperature (T2) less than T1, and is a temperature under which thetemperature control subsystem cannot handle the heating by itself and/orin a given time. If the temperature of the sensor is less than T2 (520:NO), the system may determine (522) whether the temperature of thesensor is greater than a third threshold temperature (T3). In anembodiment, the third threshold temperature (T3) is a temperature abovewhich no or reduced heating action is required for the sensor. If thetemperature of the sensor is greater than T3 (522: YES), the systemstops the heating cycle (524). In an embodiment, stopping the heatingcycle may include turning off the temperature control subsystem and/orreducing the heating effect of the temperature control subsystem.

However, if the temperature of the sensor is less than or equal to T3(522: NO), the system continues performing steps 518-522.

If the temperature of the sensor is less than or equal to T2 (520: YES)and/or the system determines that the vehicle is in an idle mode (506:YES), the system may perform steps 508-516, as discussed below.

At 508, the system may determine whether it is safe to initiate acleaning cycle. The system may determine if it safe to initiate thecleaning cycle based on a rule set that includes rules specifying thatit is unsafe to initiate the cleaning cycle upon occurrence of one ormore conditions. Examples of such conditions may include, withoutlimitation, discomfort to the passengers of the vehicle, creation ofhazardous conditions because of sensor cleaning (e.g., obstruction ofdriver view through the windshield, driver distraction when the vehiclestarts moving if it is a manned vehicle, obstruction of sensorfunctioning, etc.), high traffic area, vehicle moving at high speeds,hazardous weather conditions, vehicle movement at any speed duringcleaning cycle, or the like. Additionally and/or alternatively, the ruleset may include rules identifying conditions that are determined to besafe for initiation the cleaning cycle such as, without location,location of the vehicle, speed of the vehicle, occupancy of the vehicle,type or location of the sensor, weather conditions time of the day, orthe like, such that initiation of a cleaning cycle does not compromisethe data collected by a sensor. The inclusion of one or more of theabove conditions in the rule set may depend on, without limitation,position of the sensor in the vehicle, type of the sensor, whether ornot the vehicle is moving, anticipated start time of vehicle movement,position of vehicle passengers in the vehicle, etc. For example, if thesensor is a camera sensor for which integrity of the data collected willbe compromised if cleaning fluid is sprayed on the camera sensor, therule set may include a rule that it is unsafe to clean the sensorwhenever the vehicle is moving. Hence, the system may determine that itis not safe to initiate the cleaning cycle if the vehicle is movingand/or is going to start moving during the cleaning cycle. Similarly,for a manned vehicle, if the sensor is located on or near thewindshield, the rule set may include a rule that it is unsafe to cleanthe sensor whenever the vehicle is moving. Hence, the system maydetermine that it is not safe to initiate the cleaning cycle if thevehicle is moving and/or is going to start moving during the cleaningcycle. Similarly, if a sensor is critical to navigating through a hightraffic area (e.g., blind spot sensor), the rule set may include a rulethat it is unsafe to clean the sensor whenever the vehicle is in a hightraffic area and/or is anticipated to be in a high traffic area (basedon, for example, the navigation system data).

The system may make the determination of whether or not it is safe toinitiate a cleaning cycle based on data obtained from one or moresensors of the vehicle.

If the system determines that it is not safe to initiate a cleaningcycle (508: NO), it may cause the sensor to stop functioning (i.e., turnoff) in order to prevent sensor malfunction and/or breakdown (516).Alternatively, the system may not turn off the sensor if the sensorfunctioning is critical to the operation of the vehicle and sensormalfunction is acceptable. In another embodiment, the system may eitherinitiate a heating cycle using the temperature control subsystem of thatsensor or increase the heating effect of the temperature controlsubsystem, if it is already turned on (e.g., by increasing fan speed).

However, if the system determines that it is safe to initiate a cleaningcycle (508: YES), the system may cause a fluid heater to heat thecleaning fluid (510) and the sensor cleaning subsystem of the vehicle toinitiate a cleaning cycle (512) for the sensor using the heated cleaningfluid. The fluid heater may receive thermal energy for heating thecleaning fluid from a dedicated thermal energy source (e.g., a heater),waster heat generated by the engine (e.g., power train), and/or heatgenerated inside the vehicle cabin.

In an embodiment, initiation of a cleaning cycle causes the controllerto operate one or more valves (i.e., open and/or close) of the cleaningsubsystem to direct heated cleaning fluid from the cleaning fluidreservoir towards the sensor. The controller may control the flow rateand/or fluid pressure via a pump. In certain embodiment, the cleaningfluid is heated in the cleaning fluid reservoir itself. Alternativelyand/or additionally, a heater is configured to heat the cleaning fluidin a different reservoir. The heated cleaning fluid bring up thetemperature of the sensor within its normal operational range.

In certain embodiments, the heating cycle may be stopped (if turned onin a non-idle mode) when the cleaning cycle is turned on. Alternatively,the heating cycle may be executed in association with the cleaning cycleto, for example, cool down the sensor in a shorter time.

At 514, the system may cause the cleaning subsystem to stop the cleaningcycle. In an embodiment, stopping the cleaning cycle causes thecontroller to operate one or more valves (i.e., open and/or close) ofthe cleaning subsystem to stop the flow of cleaning fluid from thecleaning fluid reservoir towards the sensor. The system may stop thecleaning cycle upon occurrence of one or more of the following: receiptof user instructions to stop the cleaning cycle, after a certain periodof time, based on temperature data corresponding to the sensor (e.g., ifthe temperature is at least a pre-defined value above T1 if the vehicleis in idle mode, if the temperature is at least a pre-defined valueabove T2 if the vehicle is not in idle mode, or the like), determiningthat it unsafe to continue the cleaning cycle (based on the rule setdescribed above in step 208 with respect to unsafe conditions), or upondetermining that the vehicle in not in an idle mode. The pre-definedtemperature value above T2 may be a temperature value at which theprimary temperature control sub-system may be able to heat the sensor byitself. The pre-defined temperature value above T2 may be determined bytaking into account that the cleaning fluid needs some time to heat thesensor (i.e., cooling is not immediate).

While the current disclosure describes monitoring and controlling thetemperature of each individual sensor, the system may monitor and/orcontrol the temperature of a plurality of sensors. For example, incertain embodiments, the system may determine whether the temperaturecorresponding to a subset of the one or more sensors is above athreshold temperature, where the subset of the one or more sensorslocated close to each other. The threshold temperature may be greaterthan or equal to, without limitation, an average of the upper bounds ofthe operational temperature ranges of the subset of the sensors, highestof the upper bounds of the operational temperature ranges of the subsetof the sensors, lowest of the upper bounds of the operationaltemperature ranges of the subset of the sensors, or any othertemperature above which at least some of the subset of the sensors willstart to malfunction.

It will be understood to those skilled in the art that the initiation ofa cleaning cycle to bring down the temperature of a sensor does notimpact the initiation of a cleaning cycle if the sensor needs cleaningusing now or hereafter known methods. Rather, the current disclosuredescribes a method for using existing hardware or components of acleaning subsystem of a vehicle to maintain the temperature of thesensors in the vehicle within their operational range in addition tocleaning the sensors.

FIG. 6 depicts an example of internal hardware that may be included inany of the electronic components of the system, such as the controller,the one or more sensors, or a local or remote computing device in thesystem. An electrical bus 600 serves as an information highwayinterconnecting the other illustrated components of the hardware.Processor 605 is a central processing device of the system, configuredto perform calculations and logic operations required to executeprogramming instructions. As used in this document and in the claims,the terms “processor” and “processing device” may refer to a singleprocessor or any number of processors in a set of processors thatcollectively perform a set of operations, such as a central processingunit (CPU), a graphics processing unit (GPU), a remote server, or acombination of these. Read only memory (ROM), random access memory(RAM), flash memory, hard drives and other devices capable of storingelectronic data constitute examples of memory devices 525. A memorydevice may include a single device or a collection of devices acrosswhich data and/or instructions are stored. Various embodiments of theinvention may include a computer-readable medium containing programminginstructions that are configured to cause one or more processors toperform the functions described in the context of the previous figures.

An optional display interface 630 may permit information from the bus600 to be displayed on a display device 635 in visual, graphic oralphanumeric format. An audio interface and audio output (such as aspeaker) also may be provided. Communication with external devices mayoccur using various communication devices 650 such as a wirelessantenna, an RFID tag and/or short-range or near-field communicationtransceiver, each of which may optionally communicatively connect withother components of the device via one or more communication system. Thecommunication device(s) 650 may be configured to be communicativelyconnected to a communications network, such as the Internet, a localarea network or a cellular telephone data network.

The hardware may also include a user interface sensor 655 that allowsfor receipt of data from input devices 650 such as a keyboard, a mouse,a joystick, a touchscreen, a touch pad, a remote control, a pointingdevice and/or microphone. Digital image frames also may be received froma camera 620 that can capture video and/or still images.

The above-disclosed features and functions, as well as alternatives, maybe combined into many other different systems or applications. Variouscomponents may be implemented in hardware or software or embeddedsoftware. Various presently unforeseen or unanticipated alternatives,modifications, variations or improvements may be made by those skilledin the art, each of which is also intended to be encompassed by thedisclosed embodiments.

The invention claimed is:
 1. A vehicle sensor system comprising: asensor that is attached to a vehicle; a temperature monitor configuredto collect temperature data corresponding to the sensor; a processor incommunication with the temperature monitor; a sensor cleaning subsystemthat comprises a cleaning fluid reservoir and a port that is positionedto direct cleaning fluid from the reservoir to the sensor for cleaningthe sensor and heating the sensor; and a non-transitorycomputer-readable medium comprising one or more programming instructionsthat when executed by the processor, will cause the processor to:receive temperature data corresponding to the sensor from thetemperature monitor, determine whether a current temperature of thesensor is less than a threshold temperature, and in response todetermining that the current temperature is less than the firstthreshold temperature, cause the sensor cleaning subsystem to: heat thecleaning fluid, and initiate a cleaning cycle and direct the heatedcleaning fluid to the sensor to increase the current temperature of thesensor.
 2. The vehicle sensor system of claim 1, wherein the thresholdtemperature is greater than a lower bound of an operational temperaturerange of the sensor.
 3. The vehicle sensor system of claim 1, furthercomprising programming instructions that when executed by the processor,will cause the processor to, before causing the sensor cleaningsubsystem to initiate the cleaning cycle: determine whether the vehicleis in a safe to clean mode; and initiate the cleaning cycle only inresponse to determining that the vehicle is in the safe to clean mode.4. The vehicle sensor system of claim 1, further comprising programminginstructions that, when executed by the processor, will cause theprocessor to, before causing the sensor cleaning subsystem to initiatethe cleaning cycle: determine whether the vehicle is in an idle mode;and cause the sensor cleaning subsystem to initiate the cleaning cycleonly in response to determining that the vehicle is in the idle mode. 5.The vehicle sensor system of claim 4, further comprising programminginstructions that, when executed by the processor, will cause theprocessor to, in response to determining that the vehicle is not in theidle mode, cause a temperature control subsystem of the vehicle toinitiate a heating cycle to heat the sensor.
 6. The vehicle sensorsystem of claim 5, further comprising programming instructions that,when executed by the processor, will cause the processor to: determinewhether the current temperature of the sensor is less than a secondthreshold temperature; and in response to determining that the currenttemperature is less than the second threshold temperature, cause thesensor cleaning subsystem to: heat the cleaning fluid, and initiate thecleaning cycle and direct the heated cleaning fluid to the sensor toheat the sensor.
 7. The vehicle sensor system of claim 6, wherein thesecond threshold temperature is less than the first thresholdtemperature.
 8. The vehicle sensor system of claim 6, further comprisingprogramming instructions that when executed by the processor, will causethe processor to, before causing the sensor cleaning subsystem toinitiate the cleaning cycle: determine whether the vehicle is in a safeto clean mode; and initiate the cleaning cycle only in response todetermining that the vehicle is in the safe to clean mode.
 9. Thevehicle sensor system of claim 5, wherein initiation of the heatingcycle comprises at least one of the following: turn on the temperaturecontrol subsystem; increase the heating efficiency of the temperaturecontrol subsystem; or decrease the cooling efficiency of the temperaturecontrol subsystem.
 10. The vehicle sensor system of 1, furthercomprising stopping the cleaning cycle upon occurrence of one or more ofthe following: after a pre-determined time period; in response todetermining that the current temperature of the sensor is less than thefirst threshold temperature; receipt of user instructions; in responseto determining that it is unsafe to continue the cleaning cycle; or endof an idle mode of the vehicle.
 11. The vehicle sensor system of 1,wherein causing the sensor cleaning subsystem of the vehicle to heat thecleaning fluid comprises heating the cleaning fluid using thermal energyobtained from at least one of the following: waste thermal energygenerated by an engine of the vehicle; thermal energy used in a cabin ofthe vehicle; or a dedicated thermal energy source for heating thecleaning fluid.
 12. A method for heating a sensor of a vehicle, themethod comprising: receiving temperature data corresponding to thesensor from a temperature monitor associated with the sensor;determining whether a current temperature of the sensor is less than afirst threshold temperature; and in response to determining that thecurrent temperature is less than the first threshold temperature,causing a sensor cleaning subsystem of the vehicle to: heat a cleaningfluid, and initiate a cleaning cycle and direct the heated cleaningfluid to the sensor to increase the current temperature of the sensor.13. The method of claim 12, wherein the threshold temperature is greaterthan a lower bound of an operational temperature range of the sensor.14. The method of claim 12, further comprising, before causing thesensor cleaning subsystem to initiate the cleaning cycle: determiningwhether the vehicle is in a safe to clean mode; and initiating thecleaning cycle only in response to determining that the vehicle is inthe safe to clean mode.
 15. The method of claim 12, further comprising,before causing the sensor cleaning subsystem to initiate the cleaningcycle: determining whether the vehicle is in an idle mode; and causingthe sensor cleaning subsystem to initiate the cleaning cycle only inresponse to determining that the vehicle is in the idle mode.
 16. Themethod of claim 15, further comprising, in response to determining thatthe vehicle is not in the idle mode, causing a temperature controlsubsystem of the vehicle to initiate a heating cycle to heat the sensor.17. The method of claim 16, further comprising: determining whether thecurrent temperature of the sensor is less than a second thresholdtemperature; and in response to determining that the current temperatureis less than the second threshold temperature, causing the sensorcleaning subsystem to: heat the cleaning fluid, and initiate thecleaning cycle and direct the heated cleaning fluid to the sensor toheat the sensor.
 18. The method of claim 17, wherein the secondthreshold temperature is less than the first threshold temperature. 19.The method of claim 17, further comprising, before causing the sensorcleaning subsystem to initiate the cleaning cycle: determining whetherthe vehicle is in a safe to clean mode; and initiating the cleaningcycle only in response to determining that the vehicle is in the safe toclean mode.
 20. The method of claim 16, wherein initiation of theheating cycle comprises at least one of the following: turning on thetemperature control subsystem; increasing the heating efficiency of thetemperature control subsystem; or decreasing the cooling efficiency ofthe temperature control subsystem.
 21. The method of claim 12, furthercomprising stopping the cleaning cycle upon occurrence of one or more ofthe following: after a pre-determined time period; in response todetermining that the current temperature of the sensor is less than thefirst threshold temperature; receipt of user instructions; in responseto determining that it is unsafe to continue the cleaning cycle; or endof an idle mode of the vehicle.
 22. The method of claim 12, whereincausing the sensor cleaning subsystem of the vehicle to heat thecleaning fluid comprises heating the cleaning fluid using thermal energyobtained from at least one of the following: waste thermal energygenerated by an engine of the vehicle; thermal energy used in a cabin ofthe vehicle; or a dedicated thermal energy source for heating thecleaning fluid.